How often does a story about a bike lane, one particular bike lane, make it on to the front page of what is, by most accounts, the world's finest newspaper?

That is what happened on Tuesday, when the New York Times published a report about a lawsuit filed by a group of Brooklyn residents against the city of New York over a bike lane on Prospect Park West, which is the road that forms the boundary between Prospect Park itself and the prosperous, fashionable neighbourhood of Park Slope in Brooklyn.

But how often such a bike lane makes a front page splash is not the question that matters – but how and why one bike lane is such big news. A very great deal now hangs, not on the outcome of this lawsuit, but on the political and public opinion battle of which it forms a part.

What is also at stake, potentially, is the career of New York's transportation commissioner, Janette Sadik-Khan, who has been an effective and high-profile champion of public transportation, pedestrianisation projects and pro-cycling measures. And on her fate rests the whole future of transportation and traffic management public policy in the city of New York. Mayor Michael Bloomberg is under considerable pressure to admit that the lieutenant he once charged with delivering his own ambitious "greenprint" for a sustainable city, PlaNYC, has become a PR liability. If he now hangs Sadik-Khan out to dry, it will be a huge setback for PlaNYC, and a major reversal for progressive transport policy.

So how does one disputed bike lane fit in to the big picture?

As the Times reports, nearly three-quarters of Park Slope residents surveyed approve the Prospect Park West bike lane; but that figure falls to only about half of residents when you ask those who actually live on the road itself, which, having the park view, are, of course, those with the most valuable real estate but fewer parking places than they used to have. Among these disaffected residents is, by coincidence, Sadik-Khan's predecessor as the city's transportation commissioner, Iris Weinshall, whose tenure is not recalled for its visionary overhaul of city planning and traffic management. Weinshall happens to be married to Charles (Chuck) E Schumer, Democratic senator for New York.

Taking on the lawsuit, pro bono, is a high-flying corporate lawyer, Jim Walden. The website for Gibson Dunn, where he is a partner, boasts that, among other notable litigation successes, Walden got a multinational chemical company's department of justice fine reduced by $70m; helped a global financial services firm dodge a New York stock exchange investigation; and got an energy company off the hook of a criminal investigation for insider dealing. Walden was a contributor to Schumer's 2010 re-election campaign. I'm sure City Hall has a fine and admirable legal department, but $70m says this guy doesn't like to lose.

Powerful interests and very good connections are at work here. Two days before the lawsuit was launched, the Sunday edition of the New York Times's Metro section led with a feature about how much Sadik-Khan had upset people with her highhanded approach to policy-making. Putting aside the implicit sexism of the piece, there was no attempt to report the facts – the booming commerce in the newly pedestrianised Times and Herald Squares, the improvements in road safety, particularly pedestrian casualty numbers, from the traffic-calming effect of installing bike lanes, and the increase in cycle use itself. As one responding letter to the editor put it:

"One piece of actual news is hidden among all the unpleasant gossip about Janette Sadik-Kahn, the city's transportation commissioner: 'fewer people have been killed in traffic accidents on New York's streets than at any time in the past century, according to city records.' Shouldn't that have been the headline?"

But this was an old-fashioned hatchet job, which began with an anecdote designed to show Bloomberg wishes to distance himself from Sadik-Khan and ended with a quote from her appearing to predict the demise of her career as a city official. What is more, the article made occasional use of an interview with Sadik-Khan evidently recorded some weeks earlier; so clearly, this feature had sat on the stocks until an editor decided the moment was ripe. And that moment just happened to be the Sunday before the Monday when the lawsuit was filed.

Quite why the New York Times has become so partisan in this affair is mysterious. Certainly, its steady drip, drip feed of negative stories about bike lanes has been consistent. It may judge rightly that its readership demographic is more likely to be the car-owning, conventional bourgeoisie, which feels affronted by downtown bicycling bohemians and any politically-correct tribune in city hall who spends its tax dollars tearing up perfectly good parking spaces to create bike lanes. And now, the Times's better journalistic instincts may be somewhat deranged by the first few drops of blood in the water that would precede a media feeding frenzy – should Bloomberg cave and throw Sadik-Khan to the sharks.

So, these are the elements: the mayor past his idealistic, reformist phase and, frankly, losing interest in anything except his favourable public image; a talented and motivated transportation commissioner whose forthright approach to innovative policy was once heralded as decisive and visionary, but is now labelled, by a fickle media, "tactless" and insufficiently consensual; an increasingly mobilised and organised "anti" lobby, which, though small in number, has disproportionate means and influence at its disposal; and compliant mainstream media, which either always saw progressive transport policy as inherently anti-car and suspect, or which was never that interested in the technocratic stuff but certainly now senses the mayor's loss of nerve and seeks to set the agenda by making mischief.

Connect the dots, and this becomes a much more significant story than the future of one bike lane in Brooklyn, or even the career of one official. New York City justly sees itself as the world's greatest city: here, in some sense, people live the way everyone would live if they had the chance. How New York – the city that still has a uniquely low level of car ownership and use – manages its transport planning in the 21st century matters for the whole world: it is the template. If cycling is pushed back into the margins of that future, rather than promoted, along with efficient mass public transit and safe, pleasant pedestrianism, as a key part of that future, the consequences will be grave and grim.